Treatment of gasoline



Patented Sept. 15, 1942- 2,295.77: murmur or' oas'omwa Joseph A. Chenicek,

versal Oil Products Co corporation of Delaware No Drawing. Application January Serial No. 375,26:

. m. minor-to on. Chicago, lll., a

7 Claims. (CI. 44-66) This invention relates to a method for improving the stability of hydrocarbon distillates in so far as color and gum formation are concerned. More particularly the process concerns improved methods of preventing deterioration of cracked gasolines which may be stored for relatively long periods of time in the presence of air. I

The use of inhibitors to prevent the depreciation of olefin-containing hydrocarbon distillates such as cracked gasoline has been practiced. Such compounds as alkyl-substituted phenols, aminophenols, fractions of wood tar distillates, etc., have been added to cracked gasoline in relatively minor quantities, of the order of 0.001- 0.10% to inhibit the formation of objectionable oxidation p'roductsand prevent loss of color and antiknock properties of said g'asolines during storage periods. The use of inhibitors has replaced or supplemented such forms of refining as acid-treating, clay-treating, and the like. The result has been a material saving in refining costs as well as the conservation of substantial amounts of gasoline which were formerly lost in the refining steps.

The present invention ofi'ers a means of improving the inhibiting properties of gasoline gum inhibitors and of effecting material savings in the quantities of such materials which may be required adequately to preserve the valuable prop erties of gasoline.

In one specific embodiment the present invention 1s a method for preventing gum formation in hydrocarbon distillates such as cracked gasoline which comprises adding thereto a gasoline gum inhibitor together with a relatively minor quantity of an ammonium salt of an organic carboxylic acid.

Various compounds may be used including, for example, ammonium stearate, ammonium acetate, ammonium palmitate, ammonium butyrate, ammonium oleate and the like. The compounds are used in conjunction with known gasoline gum inhibitors such as N-substituted alkyl phenols, alkyl phenols, aminophenols, fractions of wood tar distillate such as hard-wood distillate boiling within the range of approximately 240-280 (3., and many others. The compounds of this invention may be added to the gasoline separately or simultaneously with the gum inhibitor, or may be mixed with the gum inhibitor and the mixture added to the gasoline.

The quantity of the ammonium salt of carboxylic acids. used in the gasoline is of the order of 0.000l-0.0l%. The exact quantity required is gum inhibitor used, the stability of the gasoline in gasoline as well as the gasoline, and the desired treated. The compounds of this invention are not of themselves gum inhibitors and the effect observed is not, therefore, such as might be expected by the mixing of two gasoline gum inhibitors. When added alone to cracked gasoline in amounts up to approximately 0.1%, little or no increase in' the oxygen bomb induction period is to be observed and storage tests indicate that no protection is obtained for the gasoline under storage conditions. However, when an inhibitor is added, the induction period with a given quantity of a gum inhibitor is markedly. increased and with the more effective compounds of this invention, more than equal weight percentages of the inhibitor can be replaced without suffering a loss in inhibitor potency. This is brought out more fully in the example herein given.

The compounds of this invention are not equivalent intheir efiects and it should be understood that they cannot necessarily be used to replace one another in the composite inhibitor with equal effects either on a weight or chemically equivalent basis.

The following example is given to illustrate the usefulness and practicability of the process, but should not be construed as limiting it to the exact conditions or compounds shown therein.

A Pennsylvania cracked gasoline had an induction period of 150 minutes according to the oxygen bomb induction period method. when 0.01% of an inhibitor comprising essentially N-butyl aminophenol was added, the induction period was 450 minutes. When 0.01% of ammonium stearate or ammonium acetate was added to the gasoline, the induction period was 150 minutes. when both the gum inhibitor and ammonium stearate or ammonium acetate were added, the induction period was 555 and 515 minutes respectively. By the ammonium salts, a substantial increase in induction period with the gum inhibitor occurred, although these salts had no inhibiting value in themselves. when the ammonium salts are used with the gum inhibitor, the quantity of inhibitor necessary to obtain a given induction period may be substantially redu I claim as my invention; a

1. In the stabilization of olefinic distillates against gum formation by the addition of gum inhibitors thereto, the method of increasing the effectiveness of the gum inhibitor which comprises incorporating into the distillate, in addition to the inhibitor, an ammonium salt of an organic cara function of the compound used and its solubility boxylic a accents characterized in that said salt is ammonium stearate.

5. Motor fuel comprising oleflnic gasoline containing a gum inhibitor and an ammonium salt of an organic carboxyiic acid.

6. Motor fuel comprising olefinic gasoline containing a gum inhibitor and ammonium acetate.

7. Motor fuel comprising olefinic gasoline containing a gum inhibitor and ammonium stearate.

JosEPn a. cmmcnk. 

